XML 238 R82.htm IDEA: XBRL DOCUMENT

Reclamation and Mine Closure (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Asset Retirement Obligation [Abstract]
Asset retirement obligation - Beginning	$ 35,197	$ 33,434	$ 34,457	$ 32,714	$ 32,714	$ 27,302
Accretion	758	742	1,500	1,466	2,911	2,648
Addition and changes in estimates		335		335	(1,073)	2,822
Settlements	(377)	(1)	(379)	(5)	(95)	(58)
Asset retirement obligation	$ 35,578	$ 34,510	$ 35,578	$ 34,510	$ 34,457	$ 32,714

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References+ Details

- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References+ Details